The rumen fermentation of lactose in the adult sheep

Abstract
1. A cross-bred sheep was fed successively with supplements of dried skim-milk or lactose. The effect of the supplements on the lactase activity of the rumen liquid was followed.2. Lactase activity was expressed as mg. lactose hydrolysed per ml. rumen liquid, or per mg. protein nitrogen. The enzymic activity fluctuated considerably after a change in the diet, and did not become constant even when the ration remained the same for 7 weeks.